When to Change the Oil in Your Boat

Like cars, boats need to have their oil changed at regular intervals. But understanding those intervals can be confusing. Boats are used differently than vehicles, oftentimes being brought out only for a few months a year and then left unused for long periods of time. Does this affect your oil? When should you change the oil in your motor?

The general rule of thumb is that engine oil should be changed every season or after every 100 hours of use, whichever occurs first. You should change the filter at the same time. Unfortunately, changing the oil in your boat is more complicated than changing the oil in your vehicle. You’ll need the following items:

An oil filter wrench which can fit any and all filters you have

Several plastic baggies that can hold a filter

A wrench that can move your drain plug

A pan that can fit underneath your engine

Alternatively, an oil drain pump along with a bucket that can hold all of the oil in your engine

Alternatively, an oil drain pump that has been fitted permanently to the drain plug

Paper towels

New and unused filters

Fresh oil that corresponds to the type recommended by your boating manufacturer

Follow these steps to change the oil:

First, run the engine or engines until they’ve reached a temperature of at least 130 degrees. It’s okay if they reach hotter temperatures; this is the bare minimum. Following this, you should drain the remaining oil either using the pump or the pan, depending on which you have. After this, replace your plug or close the engine valve.

You should use your wrench to loosen the engine’s oil filter. When it can be turned by hand, put a plastic baggie around it. Unscrew it fully with your hand. If there are drips of oil, use the paper towel to catch them and wipe them away. Leave the filter upright in the plastic bag and seal the bag.

Place the sealed bag in the box of the new filter. Then dip your finger into the new oil. Swipe it around the O-ring on top of the new filter in order to wet it. You should screw the new filter onto the motor until it’s just tight to your fingertips.

Your owner’s manual should have your manufacturer’s recommendation regarding the tightening of the screws. Check the owner’s manual to make sure that you’re using the right wrench and filter type, then tighten the filter as much as possible.

Refill your engine with the new oil. You’ll need to add at least a quart to have the oil properly reach the filter. Once this is done, wipe away any drips with your paper towel.

The main part of the oil change is complete now. You should start the boat’s engine. Don’t leave the dock; just let the engine run quietly for a few minutes. Check the dashboard and use a gauge to make sure that the oil pressure comes up properly. It’s important that there aren’t any leaks around the plugs or filters. If there are, you might not have tightened the screws enough.

If your oil leaks and tightening the screws doesn’t help, you should turn off the engine and consult a mechanic. A mechanic will be able to diagnose and fix any problems with your engine or oil filters.

Assuming there are no leakage problems, you should dispose of the old oil at a disposal facility that has been approved in your state. If there’s new oil left in the container you just used to change your oil, keep it in a safe place with your other mechanical tools.

Now you’re ready for the new season, or ready to keep sailing if you’re already midway into the season. As always, call a professional if there seem to be problems that you’re unsure how to solve.